Touch panel and manufacturing method thereof

ABSTRACT

A touch panel has a substrate having a display region and a peripheral region, a touch sensing electrode disposed in the display region of the substrate, and a peripheral circuit disposed in the peripheral region of the substrate. The touch sensing electrode is electrically connected to the peripheral circuit, and the touch sensing electrode layer includes a first portion of a patterned metal nanowire layer. The peripheral circuit includes a patterned conductive layer and a second portion of the metal nanowire layer. At least a non-conductive material of the conductive layer is between the peripheral circuit and a second peripheral circuit.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to China Application Serial Number201911413766.1, filed Dec. 31, 2019, which is herein incorporated byreference.

BACKGROUND Field of Disclosure

The present disclosure relates to a touch panel and a manufacturingmethod thereof.

Description of Related Art

Since transparent conductors have both light transmissivity and properconductivity, they can be applied to display panel or touch panelrelated devices. Generally speaking, transparent conductors can bevarious metal oxides, such as indium tin oxide (ITO), indium zinc oxide(IZO), cadmium tin oxide (CTO), or aluminum-doped zinc oxide (AZO).However, certain characteristics of these metal oxide films have madeusing these metal oxide films challenging, such as insufficientflexibility. In some cases, patterned metal oxide films may also beproblematic because the patterned metal oxide films are easily observedby users. Therefore, a variety of transparent conductors have beendeveloped today, for example, transparent conductors made of materialssuch as nanowires.

However, when using nanowires for manufacturing touch electrodes, thereare many problems to be solved in the process and structure of nanowiresand metal leads in the peripheral region. For example, laser processingis used in the traditional process to produce patterns, but laserequipment is costly. Due to the trend toward narrow bezels and thinningsubstrates, the control on laser equipment mechanism must be precise,otherwise, it is disadvantageous to mass production of narrow bezelproducts that require fine circuits.

Further, in a process of manufacturing touch sensing electrodes using alaser, the laser will remove the material in the etched area. Also, whena substrate is irradiated with laser, the problem of point-like damageon the substrate may easily occur.

Therefore, in the process of manufacturing touch sensing electrodesusing nanowire, the electrode structure must be redesigned according tothe material characteristics, such that the product can have betterperformance.

SUMMARY

According to some embodiments of the present disclosure, a method ofmanufacturing a touch panel for addressing the foregoing issues isprovided. The method has high manufacturing efficiency and processadvantages in an application in fine circuits of narrow bezel products.

According to some embodiments of the present disclosure, a touch panelis provided. The touch panel comprises a substrate having a displayregion and a peripheral region; a touch sensing electrode disposed inthe display region of the substrate; and a peripheral circuit disposedin the peripheral region of the substrate, in which the touch sensingelectrode is electrically connected to the peripheral circuit. The touchsensing electrode comprises a first portion of a metal nanowire layerthat is patterned. The peripheral circuit comprises a conductive layerand a second portion of the metal nanowire layer that are patterned. Theconductive layer comprises conductive filler particles and anon-conductive material. The non-conductive material in the conductivelayer is between the peripheral circuit and a second peripheral circuit.In one etching step, the non-conductive material in the conductive layerremains due to etching selectivity to form an isolation structurebetween adjacent peripheral circuits (i.e., between the peripheralcircuit and the second peripheral circuit).

In some embodiments of the present disclosure, the touch panel furthercomprises an overcoat disposed on the metal nanowire layer.

In some embodiments of the present disclosure, a non-conductive regionis between the peripheral circuit and the second peripheral circuit, andthe non-conductive material in the conductive layer and the overcoat aredisposed in the non-conductive region. In one etching step, due toetching selectivity, the non-conductive material in the conductive layerand the overcoat remain to form an isolation structure between theadjacent peripheral circuits.

In some embodiments of the present disclosure, the conductive layer isformed by curing a conductive slurry comprising the conductive fillerparticles and the non-conductive material.

In some embodiments of the present disclosure, with respect to theperipheral circuit, the second portion of the metal nanowire layer isbetween the conductive layer and the substrate, or the conductive layeris between the second portion of the metal nanowire layer and thesubstrate.

In some embodiments of the present disclosure, the touch sensingelectrode comprises a first touch sensing electrode disposed at an uppersurface of the substrate and a second touch sensing electrode disposedat a lower surface of the substrate.

According to some embodiments of the present disclosure, a method ofmanufacturing a touch panel is provided. The method comprises providinga substrate having a display region and a peripheral region; disposing ametal nanowire layer comprising metal nanowires and disposing aconductive layer on the substrate, in which a first portion of the metalnanowire layer is disposed in the display region, a second portion ofthe metal nanowire layer is disposed in the peripheral region, and theconductive layer is disposed in the peripheral region and comprisesconductive filler particles and a non-conductive material; andperforming a patterning step, comprising patterning the first portion ofthe metal nanowire layer disposed in the display region to form a touchsensing electrode and concurrently patterning the conductive layer andthe second portion of the metal nanowire layer disposed in theperipheral region to form a peripheral circuit, in which at least thenon-conductive material of the conductive layer that is not removedduring the pattern step is between the peripheral circuit and a secondperipheral circuit.

In some embodiments of the present disclosure, disposing the conductivelayer on the substrate comprises coating a conductive slurry comprisingthe conductive filler particles and the non-conductive material on thesubstrate and then curing.

In some embodiments of the present disclosure, performing the patterningstep comprises concurrently applying an etching liquid on the conductivelayer and the metal nanowire layer, in which an etching rate ratio ofthe etching liquid for the conductive filler particles to thenon-conductive material is at least 10.

In some embodiments of the present disclosure, the etching liquidcomprises 0.01 wt % to 80 wt % of a metal etchant and a solvent of 20 wt% to 99.9 wt % of a solvent.

According to some embodiments of the present disclosure, the metaletchant comprises (1) hypochlorous acid, permanganic acid, perchloricacid, dichromic acid, salts of at least one of the hypochlorous acid,the permanganic acid, or the dichromic acid, or a combination thereof;(2) metal-containing salts; and (3) peroxides, a mixture of peroxidesand acids, or a mixture of peroxides and chelating agents.

According to some embodiments of the present disclosure, the etchingliquid further comprises 0.1 wt % to 20 wt % of an additive.

According to some embodiments of the present disclosure, disposing themetal nanowire layer comprising the metal nanowires and disposing theconductive layer on the substrate comprises disposing the metal nanowirelayer on the substrate; disposing the conductive layer on the metalnanowire layer; and removing the conductive layer on the display region.

In some embodiments of the present disclosure, disposing the metalnanowire layer comprising the metal nanowires and disposing theconductive layer on the substrate comprises: disposing the metalnanowire layer on the substrate; coating a conductive slurry comprisingthe conductive filler particles and the non-conductive material on themetal nanowire layer in the peripheral region; and curing the conductiveslurry to form the conductive layer.

In some embodiments of the present disclosure, disposing the metalnanowire layer comprising the metal nanowires and disposing theconductive layer on the substrate comprises: coating a conductive slurrycomprising the conductive filler particles and the non-conductivematerial on the substrate in the peripheral region; curing theconductive slurry to form the conductive layer; and disposing the metalnanowire layer on the conductive layer and the substrate.

In some embodiments of the present disclosure, the method furthercomprises disposing an overcoat on the metal nanowire layer.

In some embodiments of the present disclosure, a non-conductive regionis between the peripheral circuit and the second peripheral circuit, andthe non-conductive material in the conductive layer and the overcoatdisposed in the non-conductive region are not removed during thepatterning step.

In some embodiments of the present disclosure, a non-conductive regionis between the touch sensing electrode and a second touch sensingelectrode, and the overcoat disposed in the non-conductive region is notremoved during the patterning step.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a touch panel according to someembodiments of the present disclosure.

FIG. 2 is a schematic view of manufacturing a metal nanowire layer and aconductive layer on a substrate according to some embodiments of thepresent disclosure.

FIG. 3A is a sectional schematic view along line A-A in FIG. 1.

FIG. 3B is a sectional schematic view along line B-B in FIG. 1.

FIG. 4A and FIG. 4B are variant examples corresponding to FIG. 3A andFIG. 3B.

FIG. 5 is a schematic view of a touch panel according to someembodiments of the present disclosure.

FIG. 5A is a sectional schematic view along line A-A in FIG. 5.

FIG. 5B is a sectional schematic view along line B-B in FIG. 5.

FIG. 6 is a variant example corresponding to FIG. 3A.

DETAILED DESCRIPTION

The following embodiments are disclosed with accompanying diagrams fordetailed description. For illustration clarity, many details of practiceare explained in the following descriptions. However, it should beunderstood that these details of practice do not intend to limit thepresent disclosure. That is, these details of practice are not necessaryin parts of embodiments of the present disclosure. Furthermore, forsimplifying the drawings, some of the conventional structures andelements are shown with schematic illustrations.

As used herein, “around”, “about”, or “approximately” shall generallymean within 20 percent, preferably within 10 percent, and morepreferably within 5 percent of a given value or range. Numericalquantities given herein are approximate, meaning that the term “around”,“about”, or “approximately” can be inferred if not expressly stated. Inaddition, it is noted that the terms “pattern”, “image”, and“configuration” used in the present disclosure all have the same orsimilar meanings and may be used interchangeably for convenience ofexplanation.

Examples of the present disclosure provide a touch panel 100 comprisinga substrate 110, a peripheral circuit 120 comprising a conductive layer120A and a metal nanowire layer 140A, and a touch sensing electrode TEcomprising the metal nanowire layer 140A. FIG. 1 is a schematic top viewof the touch panel 100 according to some embodiments of the presentdisclosure. The touch panel 100 in FIG. 1 comprises the substrate 110,the peripheral circuit 120, and the touch sensing electrode TE. Thenumber of peripheral circuits 120 and touch sensing electrodes TE may beone or more, and the numbers drawn in the following specific examplesand drawings are merely for illustrative purposes and do not limit thepresent disclosure. For example, in FIG. 1, 8 peripheral circuits areillustrated, including the peripheral circuit 120, the second peripheralcircuit 122, etc.

The method of manufacturing the touch panel 100 in the presentembodiment comprises providing the substrate 110, disposing the metalnanowire layer 140A comprising the metal nanowires 140 on the substrate110, disposing the conductive layer 120A on the substrate 110, andperforming a patterning step to form the touch sensing electrode TE andconcurrently form the peripheral circuit 120.

Referring to FIG. 1, the substrate 110 may have a display region VA anda peripheral region PA. The peripheral region PA is disposed on the sideof the display region VA. For example, the peripheral region PA may bedisposed around a frame-shaped region of the display region VA (namelyencompassing right side, left side, upper side, and lower side).However, in other examples, the peripheral region PA is an L-shapedregion located on the left side and lower side of the display region VA.As shown in FIG. 1, in the present example, a total of eight sets of theperipheral circuits 120 are disposed at the peripheral region PA of thesubstrate 110, and the touch sensing electrode TE is disposed at thedisplay region VA of the substrate 110. In the present example, by meansof a one-step etching process, the metal nanowire layer 140A and theconductive layer 120A in the peripheral region PA are concurrentlypatterned to form the peripheral circuit 120. Therefore, the material ofthe upper layer (e.g., the conductive layer 120A) and the lower layer(e.g., the metal nanowire layer 140A) can be patterned at apredetermined position without aligning, such that the needs ofproviding an alignment error region in the manufacturing process isreduced or avoided, thereby reducing the width of the peripheral regionPA and further fulfilling the requirement of a narrow bezel of thedisplay device and avoiding the problem of lower process yield caused bypatterning errors caused by multiple alignments. In addition, theone-step etching in the present example may only remove the conductivematerial in the metal nanowire layer 140A and the conductive layer 120A,leaving the non-conductive material remaining in the structure.

The method of manufacturing touch panel 100 in the present embodimentcomprises providing the substrate 110, disposing the metal nanowirelayer 140A comprising the metal nanowires 140 on the substrate 110,disposing the conductive layer 120A on the metal nanowire layer 140A,and performing a patterning step to form the touch sensing electrode TEand concurrently form the peripheral circuit 120. The implementation ofthe patterning step may produce a non-conductive region 136. In thenon-conductive region 136, there is no conductive material, and thenon-conductive material remains. The detailed process of the method ofmanufacturing touch panel 100 in the present embodiment is as follows.First, referring to FIG. 2, the substrate 110 is provided. In someembodiments of the present disclosure, the substrate 110 may be atransparent substrate and specifically may be a hard transparentsubstrate or a flexible transparent substrate, where the material can beselected from glass, acrylic polymethylmethacrylate (PMMA), polyvinylchloride (PVC), polypropylene (PP), polyethylene terephthalate (PET),polyethylene naphthalate (PEN), polycarbonate (PC), polystyrene (PS),cyclo olefin polymer (COP), colorless polyimide (CPI), and othertransparent materials.

Next, still referring to FIG. 2, the metal nanowire layer 140A and theconductive layer 120A are fabricated on the substrate 110. The metalnanowire layer 140A may comprise the metal nanowires 140, as shown inFIG. 2, and the metal nanowire layer 140A is located between theconductive layer 120A and the substrate 110.

The detailed forming method of the metal nanowire layer 140A in thepresent example is as follows. A dispersion or ink comprising the metalnanowires 140 is formed on the substrate 110 by a coating method and isthen dried, such that the metal nanowires 140 cover the surface of thesubstrate 110. In other words, the metal nanowires 140 may form as themetal nanowire layer 140A disposed on the substrate 110 due to thedrying and curing steps. The display region VA and the peripheral regionPA may be defined on the substrate 110, as shown in FIG. 1. Theperipheral region PA is disposed on the side of the display region VA.For example, the peripheral region PA is disposed on the region at theleft side and right side of the display region VA. However, in otherexamples, the peripheral region PA may be disposed around a frame-shapedregion of the display region VA (namely encompassing right side, leftside, upper side, and lower side), or is disposed in an L-shaped regionat adjacent sides of the display region VA. The metal nanowire layer140A may comprise a first portion formed in the display region VA and asecond portion formed in the peripheral region PA. In detail, in thedisplay region VA, the first portion of the metal nanowire layer 140Amay be directly formed on a surface of the substrate 110. While in theperipheral region PA, the second portion of the metal nanowire layer140A may be directly formed on a surface of the substrate 110.

In examples of the present disclosure, the dispersion comprising themetal nanowires 140 may be a solvent, such as water, alcohols, ketones,ethers, hydrocarbons, or an aromatic solvent (such as benzene, toluene,and xylene, but the disclosure is not limited thereto). The dispersionmay also comprise an additive, a surfactant, or an adhesive, such ascarboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC),hydroxypropyl methylcellulose (HPMC), sulfonate ester, sulfate ester,disulfonate salts, sulfosuccinic acid ester, phosphate ester, afluorine-containing surfactant, etc. The metal nanowire layer maycomprise, for example, a silver nanowire layer, a gold nanowire layer,or a copper nanowire layer. More specifically, the term “metalnanowire(s)” in the present disclosure is a collective noun that refersto a set of metal wires comprising a plurality of elemental metals,metal alloys, or metal compounds (including metal oxides). The number ofmetal nanowires does not limit the scope of the present disclosure. Adimension of at least one cross-sectional area of the metal nanowires(i.e., the diameter of the cross-sectional area) is below 500 nm, below100 nm, or below 50 nm. The so-called “wire(s)” of the metalnanostructure in the present disclosure has a high aspect ratio, such as10 to 100,000. Specifically, the aspect ratio (i.e., the ratio of thelength to the diameter of the cross-sectional area) of the metalnanowires may be 10 and above, preferably 50 and above or morepreferably 100 and above. The metal nanowires may be any metals,including but not limited to silver, gold, copper, nickel, and a silvermaterial coated with gold. Other terms such as “silk,” “fiber,” or“tube” having a dimension and an aspect ratio within the aforementionedvalue ranges are also included in the scope of the present disclosure.

The dispersion or ink comprising the metal nanowires 140 may be formedon a surface of the substrate 110 by a suitable process known in theart, including but not limited to a screen printing process, a spraycoating process, or a roller coating process. In one example, thedispersion or ink comprising the metal nanowires 140 may be coated onthe surface of the substrate 110 in continuous supply. After thecuring/drying step, the solvent or the like is evaporated, and the metalnanowires 140 are distributed on the surface of the substrate 110randomly. Preferably, the metal nanowires 140 are fixed on the surfaceof the substrate 110 without peeling, such that the metal nanowire layer140A is formed, and the metal nanowires 140 may be in contact with eachother to provide a continuous electrical current pathway, therebyforming a conductive network.

In some embodiments of the present disclosure, the metal nanowires 140may be silver nanowires or silver nanofibers, which may have an averagediameter of about 20 to 100 nanometers and an average length of 20 to100 micrometers. Preferably, the average diameter is about 20 to 70nanometers and the average length is about 20 to 70 micrometers, namely,the aspect ratio is 1000. In some embodiments, the diameter of the metalnanowires 140 may be between 70 nanometers to 80 nanometers, and thelength may be about 8 micrometers.

The detailed method of forming the conductive layer 120A in the presentexample is as follows. A metal material is formed on the metal nanowirelayer 140A by an appropriate process, such as but not limited to,coating a metal conductive slurry, for example, a silver paste (Agpaste) material on the metal nanowire layer 140A. In one example, theconductive layer 120A may be disposed on the metal nanowire layer 140A,and the conductive layer 120A is only disposed at the peripheral regionPA. The specific method may be but is not limited to coating the silverpaste material on the metal nanowire layer 140A and at the peripheralregion PA, followed by curing the silver paste material to form theconductive layer 120A. In one specific example, the temperature in thecuring step of the silver paste material is about 90° C.-110° C., andthe curing time is about 10-20 minutes. The metal conductive slurry maybe selected to be an ultraviolet (UV) hardening type conductive silverpaste. The hardening mechanism is that after a photosensitive resin inthe composition of the metal conductive material is exposed tohigh-energy radiation such as ultraviolet light, electron beam, X-ray,etc., some chemical or physical changes such as bridging, crosslinking,decomposition, or isomerization occur, which in turn change theproperties of the photosensitive resin. A suitable amount ofphotoinitiator and photosensitizer may be added to the UV hardening typeconductive silver paste to achieve the purpose of photo-initiatedpolymerization. In one example, the curing method of the metalconductive slurry may be thermal curing, room temperature curing (e.g.,curing at 20-25° C.), curing by a surface treatment agent, etc.

The metal conductive slurry in the present example is a compositematerial made by using a resin matrix as a binder, a conductive fillermaterial (such as powder of gold, silver, copper, aluminum, zinc, iron,or nickel, graphite, or some conductive compound filler particles),solvent, etc. The resin matrix can use a variety of binder/adhesive-typeresin matrix. Commonly used thermosetting adhesives are, for example,epoxy resin, organosilicone resin, polyimide resin, phenolic resin,polyurethane, acrylic resin, and other adhesive systems. The content ofthe resin matrix accounts for more than 80 wt %, the content of theconductive filler particles is about 5-50 wt %, and the content of thesolvent is about 1-10 wt %. The metal conductive slurry may alsocomprise auxiliaries, cross-linking agents, coupling agents, diluents,preservatives, toughening agents, thixotropic agents, etc. After themetal conductive slurry is cured, the solvent evaporates, and the resinmatrix forms the main structure, which mainly provides mechanicalproperties and/or adhesion performance, and the conductive fillerparticles form a conductive path. In one example, the cured metalconductive slurry constitutes the conductive layer 120A, and theconductive layer 120A may be roughly divided into conductive materials(such as the conductive filler particles) and non-conductive material(such as the resin matrix) based on their conductivity. After thepatterning step described later, the conductive material in the etchedregion is removed, and the non-conductive material in the etched regionis not removed.

For another example, the metal conductive slurry may be formed on themetal nanowire layer 140A and is between the display region VA and theperipheral region PA. Similar to the metal nanowire layer 140A, theconductive layer 120A may comprise a first portion formed in the displayregion VA and a second portion formed in the peripheral region PA. Thefirst portion of the conductive layer 120A is removed in the subsequentprocess to expose the first portion of the metal nanowire layer 140A.The second portion of the conductive layer 120A and the second portionof the metal nanowire layer 140A are patterned in the subsequent processto form the peripheral circuit 120.

In one example, the resin matrix in the metal conductive slurry maypenetrate into the gap between metal nanowires during the process due toa fluidity of the resin matrix, thereby forming part of the structure ofthe metal nanowire layer 140A.

Next, a patterning step is performed mainly for patterning the metalnanowire layer 140A in the display region VA to form the touch sensingelectrode TE, as well as concurrently patterning the conductive layer120A and the metal nanowire layer 140A in the peripheral region PA toform the peripheral circuit 120.

The present example may specifically include the following steps. First,a photosensitive material (such as photoresist) is exposed/developed(that is, the well-known yellow-light photolithography process) todefine the pattern of the touch sensing electrode TE in the displayregion VA and the pattern of the peripheral circuit 120 in theperipheral region PA. Next, an etching process is performed to producethe touch sensing electrode TE comprising the metal nanowire layer 140A(namely, the first portion of the metal nanowire layer 140A) on thedisplay region VA (see FIG. 1 and FIG. 3B), and also produce theperipheral circuit 120 comprising the metal nanowire layer 140A (namely,the second portion of the metal nanowire layer 140A) and the conductivelayer 120A (namely, the second portion of the conductive layer 120A) onthe peripheral region PA (see FIG. 1, FIG. 3A, and FIG. 3B).

In one example, an etching liquid that can simultaneously etch the metalnanowire layer 140A and the conductive layer 120A is used, such that thetouch sensing electrode TE and the peripheral circuit 120 aremanufactured in the same process. Therefore, the connection of the touchsensing electrode TE in the display region VA and the peripheral circuit120 in the peripheral region PA is able to be completed with a minimumnumber of alignments (e.g. one time), thereby avoiding the low yieldcaused by the traditional multiple alignment processes and also omittingthe alignment tolerance that is required to be reserved for an alignmentprocess, such that the width of the peripheral circuit 120 can become assmall as possible to meet the narrow bezel requirement of the displaydevice. In addition, the selected etching liquid has a high etchingselectivity between the conductive material and the non-conductivematerial. For example, the etching rate ratio between the conductivematerial and the non-conductive material is about 10 and above, 50 andabove, between 100-500, or 1000 and above.

According to one specific example, in the case where the metal nanowirelayer 140A is a silver nanolayer and the conductive layer 120A is asilver paste layer, an etching liquid that can etch copper and silver isused. For example, the composition of the etching liquid comprises about0.01 wt %-80 wt % of metal etchant, about 20 wt %-99.9 wt % of solvent,and/or about 0.1 wt %-20 wt % of additive. The metal etchant maycomprise but is not limited to (1) hypochlorous acid, permanganic acid,perchloric acid, dichromic acid, etc., salts of the foregoing acids,and/or a combination thereof; (2) metal-containing salts, such as saltsof divalent copper and trivalent iron; and (3) peroxides, a mixture ofperoxides and acids, and/or a mixture of peroxides and chelating agents.The solvent may comprise but is not limited to water and/or an organicsubstance. The organic substance may be 3-5 carbon-based monoalcohols orpolyalcohols, such as methanol, ethanol, isopropanol, ethylene glycol,propylene glycol and glycerin, or a mixture thereof. The additive maycomprise but is not limited to one or more of surfactant, defoamer, pHregulator, and inhibitor.

The surfactant may comprise but is not limited to one or more ofcationic surfactant, anionic surfactant, zwitterionic surfactant, andnonionic surfactant.

The pH regulator may comprise, but is not limited to, inorganic acids,organic acids, and/or mixtures of inorganic and organic acids. Theinorganic acids may comprise, but are not limited to, one or more ofsulfuric acid, nitric acid, hydrochloric acid, and phosphoric acid. Theorganic acids may comprise but are not limited to one or more of formicacid, acetic acid, propionic acid, oxalic acid, citric acid, lacticacid, sulfonic acid, and salicylic acid.

At this point, the touch panel 100 (such as FIG. 1) of the example inthe present disclosure can be obtained, while FIG. 3A and FIG. 3B arethe schematic views of cross-sections taken at line A-A and line B-B ofFIG. 1. Referring to FIG. 1, FIG. 3A, and FIG. 3B, the touch panel 100in the example of the present disclosure (as shown in FIG. 1), which isa single-sided touch panel, may comprise the substrate 110, theperipheral circuit 120 comprising the conductive layer 120A and themetal nanowire layer 140A, and the touch sensing electrode TE comprisingthe metal nanowire layer 140A. The touch sensing electrode TE may beelectrically connected to the peripheral circuit 120.

In detail, as shown in FIG. 3A and FIG. 3B, in some embodiments of thepresent disclosure, the peripheral circuit 120 is a composite structurelayer comprising a double-layered patterned conductive structure, whichcomprises the conductive layer 120A and the metal nanowire layer 140Abetween the conductive layer 120A and the substrate 110. The touchsensing electrode TE is formed by patterning the metal nanowire layer140A. In other words, the metal nanowire layer 140A forms as the touchsensing electrode TE in the display region VA and forms as an underlayerstructure of the peripheral circuit 120 in the peripheral region PA.Therefore, due to the conductivity of the metal nanowire layer 140A, thetouch sensing electrode TE can be electrically connected with theperipheral circuit 120 for signal transmission.

As shown in FIG. 3A and FIG. 3B, in the peripheral region PA, thenon-conductive region 136 is between the adjacent peripheral circuits120 and comprises non-conductive material (such as the resin matrix) ofthe conductive layer 120A to electrically isolate the adjacentperipheral circuits 120 and further avoid short circuit. In other words,after the patterning step, the conductive material (such as theconductive filler particles) at a specific position in the conductivelayer 120A is etched and removed. Similarly, the metal nanowires 140 atthe corresponding etching position of the metal nanowire layer 140A arealso etched and removed to form the non-conductive region 136.Therefore, in the present example, the non-conductive region 136comprises the non-conductive material of the conductive layer 120A (suchas the resin matrix) and the non-conductive material in the metalnanowire layer 140A and isolates adjacent peripheral circuits 120. Thenon-conductive material in the metal nanowire layer 140A may be anon-conductive component such as resin in the metal nanowires slurry, anon-conductive component such as the resin matrix in the metalconductive slurry overflowing to the lower layer, air, or a combinationthereof. In one example, the above-mentioned etching liquid may be usedto manufacture the aforementioned non-conductive region 136.Alternatively, the conductive layer 120A may be etched first, followedby etching the metal nanowire layer 140A. In one example, the conductivelayer 120A and the metal nanowire layer 140A that remain after etchingmay have the same or similar patterns and dimensions, such as arectangular pattern, with the same or similar widths.

As shown in FIG. 3B, in the display region VA, the non-conductive region136 is between the adjacent touch sensing electrodes TE to electricallyisolate the adjacent touch sensing electrodes TE to avoid short circuit.In other words, the non-conductive region 136 is between sidewalls ofthe adjacent touch sensing electrodes TE. In the present example, thenon-conductive region 136 may be a gap/air gap left after etching themetal nanowires 140, the non-conductive material in the metal nanowirelayer 140A that is not removed by etching, a non-conductive componentsuch as the resin matrix in the metal conductive slurry that overflowsto the lower layer, or a combination thereof, thereby isolating theadjacent touch sensing electrode TE. In one example, the aforementionedetching liquid can be used to manufacture the adjacent touch sensingelectrodes TE. In the present embodiment, the touch sensing electrodesTE are disposed in a non-interlace arrangement. For example, the touchsensing electrode TE is an electrode in a rectangular shape extendingalong a first direction D1 without interlacing with each other. However,in other embodiments, the touch sensing electrode TE may have anyappropriate shapes and the scope of the present disclosure shall not belimited. In the present embodiment, the touch sensing electrode TEadopts a single-layer configuration, in which a touch sensing positioncan be obtained by detecting the change of the capacitance value of eachof the touch sensing electrodes TE.

In the present embodiment, the touch sensing electrode TE in the displayregion VA preferably has conductivity and light transmittance.Therefore, the metal nanowire layer 140A that is used to manufacturetouch sensing electrode TE has preferably the following characteristics:the transmission to visible light (e.g. wavelength between about 400nm-700 nm) is greater than about 80%, and the surface resistance isbetween about 10 to 1000 ohms/square. Alternatively, the transmission ofthe metal nanowire layer 140A to visible light (e.g. wavelength betweenabout 400 nm-700 nm) is greater than about 85%, and the surfaceresistance is between about 50 to 500 ohms/square.

In one example, a mark 150 is further disposed in the peripheral regionPA of the substrate 110. Referring to FIG. 1 and FIG. 3A, in the sameway with the peripheral circuit 120, the mark 150 is also produced by aone-step etching of the metal nanowire layer 140A and the conductivelayer 120A, and therefore the mark 150 comprises the conductive layer120A and the metal nanowire layer 140A between the conductive layer 120Aand the substrate 110. In addition, the metal nanowire layer 140A andthe conductive layer 120A that form the mark 150 have the same orsimilar patterns and dimensions, such as circles with the same orsimilar radius, quadrilaterals with the same or similar side length, orother patterns with the same or similar cross shape, L shape, T shape,etc. The mark 150 can be widely interpreted as a pattern that does nothave electrical functions. For example, the mark 150 can be anyverification marks, patterns, or labels required in the manufacturingprocess, which are all protected by the present disclosure. The mark 150may have any possible shapes, such as circle, quadrilateral, cross,L-shape, T-shape, etc., but is not limited thereto. In one example, theupper and lower two-layer structure that forms the mark 150 and theupper and lower two-layer structure of the peripheral circuit 120 have(e.g., are adjacent to) the non-conductive region 136, and the previousdescription may be referenced for additional details.

In one example, an overcoat may be disposed on the metal nanowire layer140A and then cured, such that the overcoat and the metal nanowire layer140A constitute a composite structural layer. In one example, a polymeror a mixture thereof may be formed on the metal nanowire layer 140A bycoating. The polymer will penetrate between the metal nanowires 140 toform a filler, and a curing step is applied to form the overcoat or amatrix layer. In other words, the metal nanowires 140 can be regarded asbeing embedded in the overcoat. In one specific example, the curing stepmay be heating and baking (at a temperature of about 60° C. to about150° C.) the polymer or the mixture thereof to form the overcoat on themetal nanowire layer 140A. The present disclosure does not limit thephysical structure between the overcoat and the metal nanowire layer140A. For example, the overcoat and the metal nanowire layer 140A can bea two-layer stack, or the overcoat and the metal nanowire layer 140A cancombine with each other to form a composite layer. In the followingdescription, the metal nanowires 140 is embedded in the overcoat to forma composite layer, and the composite layer is patterned in thesubsequent process. As one example, FIG. 6 illustrates an embodiment inwhich an overcoat 152 is disposed over the metal nanowire layer 140A.

In an implementation structure with the overcoat, the aforementionedetching liquid has a high etching selectivity ratio between the metalnanowires and the overcoat material. For example, the ratio of theetching rate for metal nanowires to the etching rate for the overcoatmaterial is about 10 and above, or 50 and above, or between 100-500.Therefore, the non-conductive region 136 manufactured by etching in theperipheral region PA comprises the non-conductive material of theconductive layer 120A (such as the aforementioned resin matrix) and anunremoved overcoat material. The non-conductive region 136 manufacturedby etching in the display region VA comprises an unremoved overcoatmaterial. In other words, since the metal nanowires 140 are completelyetched, the concentration of nanowires dispersed in the non-conductiveregion 136 is zero. It is noted that since the formation of thenon-conductive region 136 involves slurry coating, curing, etching, andother steps, it is difficult to quantitatively analyze the compositionor structure thereof. In other words, the non-conductive region 136 iscomprises (or is essentially composed of) the non-conductive material ofthe conductive layer 120A and the overcoat that has not been removed byetching, but other residual materials, like non-conductive componentssuch as air, a resin in metal nanowires slurry, etc. are not excluded.However, qualitatively, the resistance of the non-conductive region 136can reach 10 times, 100 times, or more than 1000 times higher than theresistance of the conductive region and can fulfill the requirements ofpatterning.

In another example, the aforementioned etching liquid does notcompletely remove the metal nanowires 140 in the non-conductive region136. In other words, the metal nanowires 140 remain in thenon-conductive region 136, but the concentration of the remaining metalnanowires 140 is lower than a percolation threshold. The conductivity ofthe structural layer comprising the metal nanowires 140 may becontrolled by the following factors: a) the conductivity of single metalnanowires 140; b) the number of metal nanowires 140; and c) theconnectivity (also known as a contact) between the metal nanowires 140.When the concentration of the remaining metal nanowires 140 is lowerthan the percolation threshold, since the distance between the metalnanowires 140 is too far, the overall conductivity of the non-conductiveregion 136 is very low or equal to zero (or has high resistance). Thatis, the metal nanowires 140 do not provide a continuous current path inthe structural layer and cannot form a conductive network. In otherwords, the metal nanowires 140 in the non-conductive region 136 form anon-conductive network. In one example, a region or a structural layeris considered to be non-conductive when the sheet resistance is higherthan 10⁸ ohms/square, or higher than 10⁴ ohms/square, or higher than3000 ohms/square, or higher than 1000 ohms/square, or higher than 350ohms/square, or higher than 100 ohms/square. In other words, in thepresent example, the non-conductive region 136 manufactured by etchingin the peripheral region PA comprises the non-conductive material of theconductive layer 120A (such as the resin matrix), the overcoat material,and the metal nanowires 140 with a concentration lower than thepercolation threshold. Similarly, the non-conductive region 136manufactured by etching in the display region VA comprises the overcoatmaterial and the metal nanowires 140 with a concentration lower than thepercolation threshold to achieve the isolation between the adjacenttouch sensing electrodes TE. The non-conductive region 136 is notlimited to the constituent materials described above. As long as theresistance of the non-conductive region 136 can qualitatively reach 10times, 100 times, or more than 1000 times higher than the resistance ofother conductive regions, the requirements for patterning are fulfilled.

Referring to FIG. 4A and FIG. 4B, which show another example of thetouch panel 100. The description of FIG. 4A and FIG. 4B correspond tothose of FIG. 3A and FIG. 3B, and the difference between the presentexample and the previous example is at least that the conductive layer120A is disposed between the metal nanowire layer 140A and the substrate110. Same with the previous example, the metal nanowire layer 140A inthe display region VA may be patterned to form the touch sensingelectrode TE, and the conductive layer 120A and the metal nanowire layer140A in the peripheral region PA are concurrently patterned to form theperipheral circuit 120. The non-conductive region 136 in the peripheralregion PA comprises the non-conductive material of the conductive layer120A (such as the resin matrix).

According to some embodiments of the present disclosure, a double-sidedtouch panel (as in FIG. 5) is proposed. The manufacturing method thereofmay comprise manufacturing the metal nanowire layer 140A and theconductive layer 120A on a first surface (such as an upper surface) anda second surface (such as a lower surface) of the substrate 110respectively. The process is similar to that described above and is notrepeated herein.

Next, a patterning step is performed. The patterning step in the presentexample may specifically include the following steps. First, aphotosensitive material (such as photoresist) is exposed/developed (suchas a double-sided photolithography process) to define the pattern of theperipheral circuit 120 in the peripheral region PA. An etching liquidthat can concurrently etch the metal nanowire layer 140A and theconductive layer 120A is used to perform etching (reference can be madeto the composition and related description of the aforementioned etchingliquid) to manufacture a first touch sensing electrode TE1 and a secondtouch sensing electrode TE2 comprising the metal nanowire layer 140A onthe display region VA and also manufacture the peripheral circuit 120comprising the metal nanowire layer 140A and the conductive layer 120Aon the peripheral region PA. The non-conductive region 136 is betweenadjacent peripheral circuits 120 and comprises the non-conductivematerial of the conductive layer 120A (such as the aforementioned resinmatrix) to electrically isolate the adjacent peripheral circuits 120 toavoid short circuit. The process is similar to that described above andis not repeated herein.

The first touch sensing electrode TE1 and the second touch sensingelectrode TE2 are interlaced in structure with each other, and the firsttouch sensing electrode TE1 and the second touch sensing electrode TE2can form the touch sensing electrode TE for sensing touch or controllinggestures.

As shown in FIG. 5, a touch panel 100 in the example of the presentdisclosure comprises a substrate 110, a touch sensing electrode TE(namely a first touch sensing electrode TE1 and a second touch sensingelectrode TE2 formed of the metal nanowires 140) formed on upper andlower surfaces of the substrate 110, and a peripheral circuit 120 formedon upper and lower surfaces of the substrate 110. As shown in FIG. 5A,as viewed from the upper surface of the substrate 110, the first touchsensing electrode TE1 in the display region VA and the peripheralcircuit 120 in the peripheral region PA are electrically connected toeach other to transmit signals. Similarly, as shown in FIG. 5B, asviewed from the lower surface of the substrate 110, the second touchsensing electrode TE2 in the display region VA and the peripheralcircuit 120 in the peripheral region PA are electrically connected toeach other to transmit signals. The peripheral circuit 120 comprises theconductive layer 120A and the metal nanowire layer 140A, and there is anon-conductive region 136 comprising a non-conductive material of theconductive layer 120A (such as the resin matrix) between adjacentperipheral circuits 120 to electrically isolate the adjacent peripheralcircuits 120 to avoid short circuit. The specific form of thenon-conductive region 136 can be similar to that described above and isnot repeated herein.

In one example, the conductive layer 120A in the double-sided structuremay be disposed between the metal nanowire layer 140A and the substrate110. Same as the example, the metal nanowire layer 140A in the displayregion VA may be patterned to form the first touch sensing electrode TE1and second touch sensing electrode TE2, and the conductive layer 120Aand the metal nanowire layer 140A in the peripheral region PA areconcurrently patterned to form the peripheral circuit 120. Thenon-conductive region 136 in the peripheral region PA comprises thenon-conductive material (such as the aforementioned resin matrix) of theconductive layer 120A.

According to some embodiments of the present disclosure, a double-sidedtouch panel is also proposed. The manufacturing method may be formed bystacking two sets of single-sided touch panels in the same direction orin opposite directions. In an example where stacking in oppositedirections, the touch electrode of the first set of the single-sidedtouch panel is disposed facing upward (for example, nearest to the user,but not limited thereto), and the touch electrode of the second set ofthe single-sided touch panel is disposed facing downward (for example,farthest away from the user, but not limited thereto) and use an opticaladhesive or other similar adhesives to assemble and fix the substratesof two sets of touch panels, and thereby forming the double-sided touchpanel.

Preferably, the metal nanowires 140 formed in the foregoing example maybe further post-processed to increase electrical conductivity of themetal nanowires 140. The post-processing may be a process stepcomprising, for example, heating, plasma, corona discharge, UV ozone, orpressure. For example, after the step of curing and forming the metalnanowire layer 140A, a roller may be used to apply pressure thereon. Inone example, the metal nanowire layer 140A may be applied with apressure of 50 to 3400 psi, preferably 100 to 1000 psi, 200 to 800 psi,or 300 to 500 psi, by using one or more rollers. In some examples,post-processing such as heating and pressure can be performedsimultaneously. In other words, the metal nanowires 140 may be appliedwith pressure by using one or more rollers and is heated at the sametime. For example, the pressure applied by the roller is 10 to 500 psi,preferably 40 to 100 psi, and meanwhile the roller is heated to betweenabout 70° C. and 200° C., preferably to between about 100° C. and 175°C., such that the conductivity of the metal nanowire layer 140A can beincreased. In some embodiments, the metal nanowires 140 may bepreferably exposed to a reducing agent for post-treatment. For example,the metal nanowires 140 comprising the silver nanowires is preferablyexposed to a silver reducing agent for post-treatment. The silverreducing agent comprises borohydrides, such as sodium borohydride;boron-nitrides, such as dimethylaminoborane (DMAB); or gas reducingagents, such as hydrogen (H₂). The exposure time is about 10 seconds toabout 30 minutes, preferably about 1 minute to about 10 minutes. Thestep of applying pressure can be implemented in appropriate stepsaccording to actual needs.

The touch panel of the example in the present disclosure may beassembled with other electronic devices, such as a display with atouch-control function. For example, the substrate 110 may be attachedto a display component, such as a liquid crystal display component or anorganic light-emitting diode (OLED) display component, and the substrate110 and the display component can be laminated with an optical adhesiveor other similar adhesives. The touch sensing electrode TE can also belaminated by using an optical adhesive and an outer cover layer (such asprotective glass). The touch panel of the present disclosure can beapplied on electronic devices such as portable phones, tablet computers,laptop computers, etc.

The structure, materials, and manufacturing processes of the differentexamples of the present disclosure can reference each other and are notlimited to the foregoing specific embodiments.

In some embodiments of the present disclosure, the conductive layer inthe peripheral region may in direct contact with the metal nanowirelayer to form the peripheral circuit. Therefore, as a whole, the metalnanowires in the metal nanowire layer and the peripheral circuit willform a direct-contact and low-impedance signal transmission path, whichis used to transmit the control signal and touch-sensing signal betweenthe touch sensing electrode and an external controller. Moreover, due tothe low impedance characteristic, the loss of signal transmission isreduced, thereby solving the problem of excessively high contactimpedance in traditional structures.

In some embodiments of the present disclosure, after etching, thenon-conductive material (such as organic resins, etc.) may remain in theetched region, thereby obtaining advantages of smaller resolution andmass production. The present disclosure can avoid the use of lasertechnology to reduce process time (the processing time is reduced byabout 25%-35%) and greatly increase production efficiency.

In some embodiments of the present disclosure, the composite structurallayer of the peripheral circuit can be formed in a single etchingprocess, and the application in the manufacturing of touch panel cansimplify the patterning process of the peripheral circuit, thus havingthe advantages of simple process, rapid manufacturing, and lowmanufacturing cost.

In some embodiments of the present disclosure, the composite structurelayer of the peripheral circuit can be formed in a single etchingprocess, so the number of alignments required in the process can bereduced, thereby avoiding errors in the alignment step to improveprocess yield.

In some embodiments of the present disclosure, the composite structurelayer of the peripheral circuit can be formed in a single etchingprocess, such that the alignment tolerance that is reserved for analignment process can be omitted, and the width of the peripheral regionis effectively reduced.

In some embodiments of the present disclosure, the foregoing process canbe combined with roll-to-roll production technology for continuous,large batch production of single-sided/double-sided electrode structuretouch panels.

Although the present disclosure has been disclosed in variousembodiments as above, it is not used to limit the present invention. Itwill be apparent to those skilled in the art that various modificationsand variations can be made to the structure of the present inventionwithout departing from the scope or spirit of the invention.

What is claimed is:
 1. A touch panel, comprising: a substrate having adisplay region and a peripheral region; a touch sensing electrodedisposed in the display region of the substrate; and a peripheralcircuit disposed in the peripheral region of the substrate, the touchsensing electrode being electrically connected to the peripheralcircuit, wherein, the touch sensing electrode comprises a first portionof a metal nanowire layer that is patterned, the peripheral circuitcomprises a conductive layer and a second portion of the metal nanowirelayer that are patterned, the conductive layer comprises conductivefiller particles and a non-conductive material in which the conductivefiller particles are embedded, the second portion of the metal nanowirelayer and a combination of the conductive filler particles and thenon-conductive material overlap in a direction perpendicular to a topsurface of the substrate, and the non-conductive material in theconductive layer is further between the peripheral circuit and a secondperipheral circuit.
 2. The touch panel of claim 1, further comprising anovercoat disposed on the metal nanowire layer.
 3. The touch panel ofclaim 2, wherein a non-conductive region is between the peripheralcircuit and the second peripheral circuit, and the non-conductivematerial in the conductive layer and the overcoat are disposed in thenon-conductive region.
 4. The touch panel of claim 2, wherein anon-conductive region is between the touch sensing electrode and asecond touch sensing electrode, and the overcoat is disposed in thenon-conductive region.
 5. The touch panel of claim 1, wherein theconductive layer is formed by curing a conductive slurry comprising theconductive filler particles and the non-conductive material.
 6. Thetouch panel of claim 1, wherein, with respect to the peripheral circuit,the second portion of the metal nanowire layer is between the conductivelayer and the substrate, or the conductive layer is between the secondportion of the metal nanowire layer and the substrate.
 7. The touchpanel of claim 1, wherein the touch sensing electrode comprises a firsttouch sensing electrode disposed at an upper surface of the substrateand a second touch sensing electrode disposed at a lower surface of thesubstrate.
 8. A method of manufacturing a touch panel, comprising:providing a substrate having a display region and a peripheral region;disposing a metal nanowire layer comprising metal nanowires anddisposing a conductive layer on the substrate, a first portion of themetal nanowire layer being disposed in the display region, a secondportion of the metal nanowire layer being disposed in the peripheralregion, and the conductive layer being disposed in the peripheral regionand comprising conductive filler particles and a non-conductive materialin which the conductive filler particles are embedded, the secondportion of the metal nanowire layer and a combination of the conductivefiller particles and the non-conductive material overlapping in adirection perpendicular to a top surface of the substrate; andperforming a patterning step, comprising patterning the first portion ofthe metal nanowire layer disposed in the display region to form a touchsensing electrode and concurrently patterning the conductive layer andthe second portion of the metal nanowire layer disposed in theperipheral region to form a peripheral circuit, wherein at least thenon-conductive material of the conductive layer that is not removedduring the patterning step is further between the peripheral circuit anda second peripheral circuit.
 9. The method of claim 8 for manufacturinga touch panel, wherein disposing the conductive layer on the substratecomprises coating a conductive slurry comprising the conductive fillerparticles and the non-conductive material on the substrate and thencuring.
 10. The method of claim 8 for manufacturing a touch panel,wherein performing the patterning step comprises concurrently applyingan etching liquid on the conductive layer and the metal nanowire layer,wherein an etching rate ratio of the etching liquid for the conductivefiller particles to the non-conductive material is at least
 10. 11. Themethod of claim 10 for manufacturing a touch panel, wherein the etchingliquid comprises 0.01 wt % to 80 wt % of a metal etchant and 20 wt % to99.9 wt % of a solvent.
 12. The method of claim 11 for manufacturing atouch panel, wherein the metal etchant comprises: hypochlorous acid,permanganic acid, perchloric acid, dichromic acid, salts of at least oneof the hypochlorous acid, the permanganic acid, or the dichromic acid,or a combination thereof; metal-containing salts; and peroxides, amixture of peroxides and acids, or a mixture of peroxides and chelatingagents.
 13. The method of claim 11 for manufacturing a touch panel,wherein the etching liquid further comprises 0.1 wt % to 20 wt % of anadditive.
 14. The method of claim 8 for manufacturing a touch panel,wherein disposing the metal nanowire layer comprising the metalnanowires and disposing the conductive layer on the substrate comprises:disposing the metal nanowire layer on the substrate; disposing theconductive layer on the metal nanowire layer; and removing theconductive layer on the display region.
 15. The method of claim 8 formanufacturing a touch panel, wherein disposing the metal nanowire layercomprising the metal nanowires and disposing the conductive layer on thesubstrate comprises: disposing the metal nanowire layer on thesubstrate; coating a conductive slurry comprising the conductive fillerparticles and the non-conductive material on the metal nanowire layer inthe peripheral region; and curing the conductive slurry to form theconductive layer.
 16. The method of claim 8 for manufacturing a touchpanel, wherein disposing the metal nanowire layer comprising the metalnanowires and disposing the conductive layer on the substrate comprises:coating a conductive slurry comprising the conductive filler particlesand the non-conductive material on the substrate in the peripheralregion; curing the conductive slurry to form the conductive layer; anddisposing the metal nanowire layer on the conductive layer and thesubstrate.
 17. The method of claim 8 for manufacturing touch panel,further comprising disposing an overcoat on the metal nanowire layer.18. The method of claim 17 for manufacturing touch panel, wherein anon-conductive region is between the peripheral circuit and the secondperipheral circuit, and the non-conductive material in the conductivelayer and the overcoat disposed in the non-conductive region are notremoved during the patterning step.
 19. The method of claim 17 formanufacturing touch panel, wherein a non-conductive region is betweenthe touch sensing electrode and a second touch sensing electrode, andthe overcoat disposed in the non-conductive region is not removed duringthe patterning step.
 20. A touch panel, comprising: a substrate having adisplay region and a peripheral region; a touch sensing electrodedisposed in the display region of the substrate; and a peripheralcircuit disposed in the peripheral region of the substrate, the touchsensing electrode being electrically connected to the peripheralcircuit, wherein, the touch sensing electrode comprises a first portionof a metal nanowire layer that is patterned, the peripheral circuitcomprises a conductive layer and a second portion of the metal nanowirelayer that are patterned, the conductive layer comprises conductivefiller particles and a non-conductive material in which the conductivefiller particles are embedded, and the non-conductive material in theconductive layer is further between the peripheral circuit and a secondperipheral circuit.